Not applicable.
This invention relates to suction cups, specifically to a suction cup with a mechanism for providing enhanced holding power when a force is applied in one direction, and release of the suction cup when a force is applied in the opposite direction.
Suction cups are often used to temporarily attach a variety of objects to host surfaces. When such host surface is vertical, the suction cup must withstand the sheer force exerted upon it by the weight of the object. In most cases, the fail-point of the suction cup occurs when the stem of the suction cup, to which the object is attached, deflects under the weight of the object until it distorts the flange of the cup sufficiently to cause the cup to lose it""s suction. Additionally, if the resilience of the cup material is increased to increase suction and provide for more rigidity in the cup in order to resist this distortion, and thus provide greater sheer strength, the release of the suction cup becomes increasingly difficult. Removal is also difficult where the placement of the suction cup on the object, or the size and shape of the object, does not allow access by the user""s fingers to the edge of the suction cup to lift it from the surface and release the suction.
Several types of hold and/or release mechanisms for suction cups have been proposed. None of the proposals achieves both functions from a single element. Most involve complex mechanisms with numerous parts, including valves, levers, cams, filaments, or straps. None provide their benefit selectively based on the direction of force applied to the suction cup. A few examples are given below.
U.S. Pat. No. 5,029,786 by Wu is a two-part device comprising a suction cup and a separate frame which attaches to the cup to provide supplemental resilience to the cup outwardly from the host surface in order to provide increased holding power.
U.S. Pat. No. 5,133,524 (parent) and 5,176,346 (continuation in part) by Liu propose a system similar to Wu, with a separate resilient member attached to the suction cup to provide supplemental resilience and increased holding power.
Both Wu and Liu illustrate an important principle: suction, and thus holding power, is increased by applying force to the center of the suction cup outwardly away from the host surface, provided the outer flange of the cup is protected from distortion, and hence failure, under such force. However, both proposals suffer from several deficiencies. Neither provides for a means for conveniently releasing the hold of the suction cup when desired. Both require the manufacture and assembly of two or more separate pieces in order to function.
U.S. Pat. No. 5,087,005 by Holoffet et al. relies again on the principle illustrated by Wu and Liu. It employs a rather complex assembly of parts to provide force to the center of the suction cup outward from the host surface while supporting the stability of the outer flange of the cup. Again, the device requires the manufacture and assembly of two or more parts, and makes no provision for release of the suction cup.
U.S. Pat. No. 6,318,685 B1 by Huber proposes a two-part device comprising a suction cup with a non-releasably attached connecting element. The connecting element includes a flange portion which attaches to the suction cup on its concave face to stabilize the cup from distortion when force is applied to it. Again, this requires the manufacture and assembly of two or more separate parts. No provision for release of the suction cup is offered.
U.S. Pat. No. 6,143,391 by Barnes et al. proposes a one-piece, dual-material suction cup wherein a highly compliant material for adhesion to a host surface lines the concave surface of a suction cup formed of a highly resilient material to provide outward force away from the host surface. The proposal includes a release mechanism in the form of a release tab attached to the rim of the suction cup which must penetrate the mounted object and be manually manipulated by the user to achieve release of the suction cup.
U.S. Pat. No. 5,381,990 5,651,520 and 5,711,501 by Belokin et al. propose a releasable suction cup comprising a suction cup with a valve assembly for selectively closing or opening a bore which passes through the suction cup to allow release of the vacuum. The device requires the manufacture and assembly of two or more parts. No provision for enhanced holding power is included.
U.S. Pat. No. 5,176,357 by Hobart proposes a suction cup with a release mechanism comprising a lever attached to the suction cup for lifting the cup""s outer flange from the host surface, thus releasing the vacuum. This mechanism requires that the lever be manually manipulated by the user, and thus requires that the lever either penetrate a portion of the mounted object, or be used only on objects whose size and shape allow for access to the lever. No provision for enhanced holding power is included.
U.S. Pat. No. 5,405,112 by Trethewey proposes a suction cup with a release mechanism comprising a lever and strap arrangement wherein a strap, attached at one end to the outer flange of the suction cup, penetrates the mounted object and attaches at it""s other end to a lever which must be manipulated by the user to accomplish release of the vacuum. The device requires the manufacture and assembly of two or more parts. No provision for enhanced holding power is included.
U.S. Pat. No. 5,454,540 by McPherson et al. proposes a suction cup release mechanism comprising a lever pivotally mounted to a support, and a linkage member attached to the outer flange of the suction cup. This mechanism requires that the lever be manually manipulated by the user, and thus requires that either the lever or the linkage member penetrate a portion of the mounted object, or be used only on objects whose size and shape allow for access to the lever. The device requires the manufacture and assembly of two or more parts. No provision for enhanced holding power is included.
U.S. Pat. No. 5,511,752 by Tretheway proposes a suction cup with a release mechanism comprising a valve assembly. The device requires the manufacture and assembly of two or more parts. No provision for enhanced holding power is included.
U.S. Pat. No. 6,375,143 B1 by Burns proposes a suction cup with a release mechanism comprising a tab formed integral with the rim of the suction cup, and a filament attached at one end to the tab. The filament then penetrates the attached object where it can be manipulated by the user to achieve release of the vacuum. The device requires the manufacture and assembly of two or more parts. No provision for enhanced holding power is included.
U.S. Pat. No. 4,846,429 by Scheurer et al. proposes a suction cup with a base assembly, and a release mechanism comprising a slack flexible lever extending between the base assembly and the suction cup. Release is accomplished by rotation of the attached object relative to the host surface, away from the flexible lever until the lever is drawn taught, at which point the lever lifts the rim of the suction cup and releases the vacuum. While this mechanism would work in selected applications where the mounted object can either be rotated relative to the host surface, or is of flexible composition, it would be inoperable when rigid objects were involved which due to size or shape or relation to the host surface did not lend themselves to rotation away from the host surface to affect release. In addition, no provision for enhanced holding power is included.
The present invention pertains to a suction cup which provides enhanced holding power against force applied in one direction, and release of the suction cup when force is applied in the opposite direction. The mechanism comprises a single element, made integral with the suction cup and thus requires no assembly of parts. The hold/release mechanism comprises a rigid or semi-rigid triangular web spanning from the upper portion of the suction cup""s stem radially outward to the rim of the cup, and filling in the remaining space between cup and stem.
When force is applied to the suction cup in the direction towards the hold/release member, (that is, the hold/release member lies on the side of the suction cup furthest from the direction of the force) the member acts as a lever, the fulcrum of which approximates the point where the member meets the outer rim of the cup. This lever action directs the force outward, away from the host surface, providing enhanced suction. At the same time, the presence of the rigid or semi-rigid element against the stem stabilizes the stem against deflection which would normally result in the ultimate distortion of the cup and failure of the vacuum.
When force is applied a direction opposite the hold/release member, the hold/release member again acts as a lever. In this instance, the fulcrum approximates the point where the hold/release member meets the base of the stem. The minutest deflection of the stem, unsupported against force in this direction, causes this lever to transfer and amplify the force and movement to lift the outer rim of the suction cup away from the host surface resulting in release of the cup.
This invention has broad application and is especially useful in instances where the host surface is vertical or nearly vertical, and where the size and/or shape of the mounted object prevent direct access to the suction cup to effect manual release by use of the fingers. In fact, it is anticipated that this technology will allow for applications of suction cups not before possible due to the issue of non-accessibility to accomplish release of the cup.
It is therefore an object of the present invention to provide a suction cup which has enhanced holding power and convenient releasability within a one-piece construction.
Accordingly, several objects and advantages of my invention are:
(a) to provide a suction cup with enhanced holding power, especially in applications on vertical surfaces;
(b) to provide a suction cup which can be easily released without direct manipulation of the cup by the user;
(c) to provide a suction cup whose hold/release features are selectable based on direction of applied force;
d) to provide a suction cup which is of one-piece construction and requires no assembly of parts;
e) to provide a suction cup which will work with objects of any size or shape without compromise of the object""s integrity;
f) to provide a suction cup which can be inexpensively produced.